Audio streams recorded as music records, sounds of live scenes or speech may sometimes contain popping sounds. A popping sound is characterized by a short burst of high volume. It is usually introduced by faulty recording equipment, badly adjusted electronic equipment, static electricity or even incidents happening during the recording session (e.g. collisions with a microphone during the recording session). Popping sounds may also be introduced as side effects that accompany audio data processing using numerical methods. For example, a numerical manipulation of audio data may introduce square waveforms that are the origin of the appearance of high frequency spikes when the audio stream is passed through filters which are generally present in one form or another in playback devices.
Popping sounds are usually uncomfortable to the human ear. It is always desirable to remove popping sounds from audio streams, or at least attenuate their amplitude to a level that does not cause discomfort. A simple way of removing a popping sound from an audio stream is to reduce the amplitude of the audio stream at the location where the popping happens. The process may involve digitizing the audio data that can be used to locate high amplitude that surpasses a predetermined threshold, then correcting the amplitude at those locations.
Existing tools for manipulating audio data do not provide means to visually and easily identify the locations where the amplitude of an audio stream surpasses a comfortable level of listening, and allow the user to interactively alter the audio stream amplitudes at the affected locations.
Therefore, there is a need for a method for users to graphically indicate locations of audible overload conditions, automatically locate those locations, and allow the user to interactively alter the audio stream.